Which of the following is an example of gravitational potential energy:
A car racing along a road at 80 mph
A rock on the top of a cliff
A turtle crawling along the ground
A roller coaster at the bottom of a hill
The Correct Answer and Explanation is :
The correct answer is:
A rock on the top of a cliff
Explanation:
Gravitational potential energy is the energy stored in an object due to its position relative to a gravitational field, typically Earth’s. This type of potential energy depends on the object’s mass, the height of its position, and the strength of the gravitational field it’s in. The formula for gravitational potential energy (GPE) is:
[
GPE = m \times g \times h
]
where:
- m is the mass of the object,
- g is the acceleration due to gravity (approximately 9.8 m/s² on Earth),
- h is the height above a reference point, usually the ground.
In this question, we can look at each option to see which best fits the concept of gravitational potential energy.
- A car racing along a road at 80 mph: This option represents kinetic energy, not gravitational potential energy, because the car’s energy is due to its motion along the road, not its position in a gravitational field.
- A rock on the top of a cliff: This option is correct because the rock has stored potential energy due to its position high above the ground. If the rock falls, gravity would accelerate it downwards, converting its gravitational potential energy into kinetic energy.
- A turtle crawling along the ground: This option doesn’t involve gravitational potential energy as it’s close to the ground and has only kinetic energy due to its movement.
- A roller coaster at the bottom of a hill: This option also lacks gravitational potential energy because it’s at the lowest point, where it’s actually at maximum kinetic energy and minimal potential energy.
Thus, a rock on the top of a cliff is the best example, as its elevated position stores potential energy that could be converted to motion if it falls.